ENGINE (DIAGNOSTICS)(H4DOTC DIESEL) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)

DTC DETECTING CONDITION:

Detected when two consecutive driving cycles with fault occur.

TROUBLE SYMPTOM:

• Poor driving performance

• Poor acceleration

CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode and Inspection Mode .

WIRING DIAGRAM:

STEP	CHECK	YES	NO
1.CHECK FOR ANY OTHER DTC ON DISPLAY.	Is any other DTC displayed?	Check the appropriate DTC using the “List of Diagnostic Trouble Code (DTC)”.
2.CHECK FUEL DELIVERY LINE (LOW PRESSURE LINE). Check for damage in fuel delivery line (low pressure line), leaks at connection, and air entering into line. NOTE: To check for air in the system, replace the fuel hose between the fuel filter assembly to the fuel pump with an appropriate size clear oil proof/heat proof hose, and check the condition of the fuel when the engine is idled. After completing the check, make sure to restore the original fuel hose, and fill the fuel system by operating the priming pump.	Is there damage in fuel delivery line (low pressure line), leaks at connection, and air entering into line?	Identify the faulty parts, and repair. NOTE: In this case, repair the following item: • Air entering by fuel running out: start the engine to bleed the air completely. • Other than air entering by fuel running out: replace the faulty part.
3.CHECK DTC. 1) Clear the memory using the Subaru Select Monitor or general scan tool. NOTE: For detailed procedures, refer to “Clear Memory Mode”. 2) Perform the “Inspection Mode” to check DTC.	Is the same DTC as current diagnosis output?		The circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.
4.CHECK COMMON RAIL PRESSURE SENSOR. 1) Disconnect the connector from the common rail pressure sensor. 2) Measure the resistance between common rail pressure sensor terminals. Terminals No. 1 — No. 2: No. 2 — No. 3:	Is the resistance No. 1 — No. 2: approx. 13.7 kΩ and No. 2 — No. 3: approx. 2.5 kΩ?		Replace the common rail assembly.
5.CHECK COMMON RAIL PRESSURE. Read the data of “Target Common Rail Pressure” and “Common rail pressure” using Subaru Select Monitor. NOTE: For detailed operation procedures, refer to “READ CURRENT DATA FOR ENGINE”.	Does “Common rail pressure” change in response to “Target Common Rail Pressure”?	The circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.	Inspect using “Diagnostic Procedure without Diagnostic Trouble Code (DTC)”.